iOS app development involves creating software applications for Apple's iOS operating system, which runs on iPhone, iPad, and iPod Touch devices. This process includes designing, coding, testing, and deploying apps that are specifically tailored for Apple's hardware.

The timeline for developing an iOS app can vary depending on several factors including the complexity of the app, the features required, the design specifications, and the number of revisions needed. Generally, simple apps might take 3-4 months, while more complex apps could take 6 months or more.

The cost of iOS app development can vary widely based on the app’s complexity, the experience level of the developers, the geographical location of the development team, and other project requirements. Prices can range from a few thousand dollars for a basic app to hundreds of thousands of dollars for a feature-rich, custom-built app.

The testing phase typically involves several stages including unit testing, integration testing, and user acceptance testing. This phase is crucial to ensure the app is stable, secure, and performs well under different conditions. We also perform test runs on various devices to ensure compatibility and usability.

Security is a top priority in our development process. We implement several security measures including data encryption, secure authentication mechanisms, and compliance with all relevant privacy laws and standards to ensure user data is protected.